unitSphere = ParametricPlot3D[{Sin[[Theta]] Cos[[Phi]], Sin[[Theta]] Sin[[Phi]], Cos[[Theta]]}, {[Theta], 0, Pi}, {[Phi], 0, 2 Pi}, PlotRange -> 1, PlotStyle -> Directive[Opacity[0]], Mesh -> {11, 0}, MeshStyle -> GrayLevel[0.7], BoxRatios -> {1, 1, 1}]

rad = 0.4;
plot = ParametricPlot3D[{rad*Sin[[Theta]] Cos[[Phi]], rad*Sin[[Theta]] Sin[[Phi]], rad*Cos[[Theta]]}, {[Theta], 0, [Pi]}, {[Phi], 0, 2 [Pi]},ColorFunction -> (ColorData["Rainbow"][#3] &)]